This invention relates to a magnetic resonance apparatus, comprising a magnet system for generating a steady magnetic field, a coil system for generating gradient fields, and at least one RF coil which is tuned to a predetermined frequency and which is connected, via a connection circuit, to a transmission and/or receiving device for RF signals.
An example of such an apparatus is known from EP-A-0 083 728. The cited document explains that it is important to make the bandwidth in which an RF receiving coil can receive magnetic resonance signals generated by an object to be examined wider than the natural bandwidth of the coil. To this end, the known apparatus comprises an RF receiving coil which forms a part of a wide band impedance transforming network. This network comprises two coupled resonant circuits, the RF coil itself forming part of one of these resonant circuits and hence of the network itself. To this end, the RF coil should satisfy given requirements imposed by the network. As a result the designer is not free with respect to the choice of the construction of the RF coil. Optimum matching of the RF coil to the object of the measurements to be performed by means of this coil, therefore, will not always be possible. Moreover, it is not apparent from the cited document whether the RF coil can also be used as a transmission coil and if so, what steps are to be taken in that case.